We develop a model of portfolio choice to nest the views of Keynes - who advocates concentration in a few familiar assets - and Markowitz - who advocates diversification across assets. We rely on the concepts of ambiguity and ambiguity aversion to formalize the idea of an investor’s...

An important question in international finance is to what extent stock return volatility is influenced by country location, industry affiliation, and global factors. This Paper develops a new methodology to measure these effects, in which portfolios mimicking ‘pure’ country and industry...

We examine aggregate idiosyncratic volatility in 23 developed equity markets, measured using various methodologies, and we find no evidence of upward trends when we extend the sample till 2008. Instead, idiosyncratic volatility appears to be well described by a stationary autoregressive process...

This paper presents new stylized facts on the distribution of the home bias at the fund level. We find (i) a large heterogeneity in the degree of home bias across mutual funds; (ii) a positive correlation between the size of funds and home bias; and (iii) a positive correlation between the size...